A South Carolina man died after his wife allegedly poisoned his drinks with eye drops, police say.

Lana Sue Clayton is charged with murder and unlawful malicious tampering of food after autopsy tests revealed her husband, Stephen, died from poisonous levels of tetrahydrozoline — an ingredient in over-the-counter eye drops.

Clayton, 52, admitted to police she snuck eye drops into her husbands' water between July 19 and July 21.

Tetrahydrozoline poisoning can induce comas, stop breathing, blur vision and cause seizures, according to the U.S. National Library of Medicine. Children who swallow even 1 to 2 milliliters can suffer “serious adverse events." It's added to eye drops and nasal sprays to reduce redness.

Stephen Clayton died on July 21 at their home in Clover from the poisoning. A motive for the poisoning wasn't clear.